unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, lr;
unsigned long stack_page;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = 4096 + (unsigned long)p;
fp = thread_saved_fp(p);
do {
if (fp < stack_page || fp > 4092+stack_page)
return 0;
lr = pc_pointer (((unsigned long *)fp)[-1]);
if (!in_sched_functions(lr))
return lr;
fp = *(unsigned long *) (fp - 12);
} while (count ++ < 16);
return 0;
}
static unsigned long get_wchan(struct task_struct *p)
{
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
#if defined(__i386__)
{
unsigned long ebp, esp, eip;
unsigned long stack_page;
int count = 0;
stack_page = (unsigned long)p;
esp = p->tss.esp;
if (!stack_page || esp < stack_page || esp >= 8188+stack_page)
return 0;
/* include/asm-i386/system.h:switch_to() pushes ebp last. */
ebp = *(unsigned long *) esp;
do {
if (ebp < stack_page || ebp >= 8188+stack_page)
return 0;
eip = *(unsigned long *) (ebp+4);
if (eip < first_sched || eip >= last_sched)
return eip;
ebp = *(unsigned long *) ebp;
} while (count++ < 16);
}
#elif defined(__alpha__)
/*
* This one depends on the frame size of schedule(). Do a
* "disass schedule" in gdb to find the frame size. Also, the
* code assumes that sleep_on() follows immediately after
* interruptible_sleep_on() and that add_timer() follows
* immediately after interruptible_sleep(). Ugly, isn't it?
* Maybe adding a wchan field to task_struct would be better,
* after all...
*/
{
unsigned long schedule_frame;
unsigned long pc;
pc = thread_saved_pc(&p->tss);
if (pc >= first_sched && pc < last_sched) {
schedule_frame = ((unsigned long *)p->tss.ksp)[6];
return ((unsigned long *)schedule_frame)[12];
}
return pc;
}
#elif defined(__mips__)
/*
* The same comment as on the Alpha applies here, too ...
*/
{
unsigned long schedule_frame;
unsigned long pc;
pc = thread_saved_pc(&p->tss);
if (pc >= (unsigned long) interruptible_sleep_on && pc < (unsigned long) add_timer) {
schedule_frame = ((unsigned long *)(long)p->tss.reg30)[16];
return (unsigned long)((unsigned long *)schedule_frame)[11];
}
return pc;
}
#elif defined(__mc68000__)
{
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
stack_page = (unsigned long)p;
fp = ((struct switch_stack *)p->tss.ksp)->a6;
do {
if (fp < stack_page+sizeof(struct task_struct) ||
fp >= 8184+stack_page)
return 0;
pc = ((unsigned long *)fp)[1];
/* FIXME: This depends on the order of these functions. */
if (pc < first_sched || pc >= last_sched)
return pc;
fp = *(unsigned long *) fp;
} while (count++ < 16);
}
#elif defined(__powerpc__)
{
unsigned long ip, sp;
unsigned long stack_page = (unsigned long) p;
int count = 0;
sp = p->tss.ksp;
do {
sp = *(unsigned long *)sp;
if (sp < stack_page || sp >= stack_page + 8188)
return 0;
if (count > 0) {
ip = *(unsigned long *)(sp + 4);
if (ip < first_sched || ip >= last_sched)
return ip;
}
} while (count++ < 16);
}
#elif defined(__arm__)
{
unsigned long fp, lr;
unsigned long stack_page;
int count = 0;
stack_page = 4096 + (unsigned long)p;
fp = get_css_fp (&p->tss);
do {
if (fp < stack_page || fp > 4092+stack_page)
return 0;
lr = pc_pointer (((unsigned long *)fp)[-1]);
if (lr < first_sched || lr > last_sched)
return lr;
fp = *(unsigned long *) (fp - 12);
} while (count ++ < 16);
}
#elif defined (__sparc__)
{
unsigned long pc, fp, bias = 0;
unsigned long task_base = (unsigned long) p;
struct reg_window *rw;
int count = 0;
#ifdef __sparc_v9__
bias = STACK_BIAS;
#endif
fp = p->tss.ksp + bias;
do {
/* Bogus frame pointer? */
if (fp < (task_base + sizeof(struct task_struct)) ||
fp >= (task_base + (2 * PAGE_SIZE)))
break;
rw = (struct reg_window *) fp;
pc = rw->ins[7];
if (pc < first_sched || pc >= last_sched)
return pc;
fp = rw->ins[6] + bias;
} while (++count < 16);
}
#elif defined (__s390__)
{
unsigned long ksp, backchain, ip;
unsigned long stack_page;
int count = 0;
stack_page = (unsigned long)p;
ksp = p->tss.ksp;
if (!stack_page || ksp < stack_page || ksp >= 8188+stack_page)
return 0;
backchain = (*(unsigned long *) ksp) & 0x7fffffff;
do {
if (backchain < stack_page || backchain >= 8188+stack_page)
return 0;
ip = (*(unsigned long *) (backchain+56)) & 0x7fffffff;
if (ip < first_sched || ip >= last_sched)
return ip;
backchain = (*(unsigned long *) backchain) & 0x7fffffff;
} while (count++ < 16);
}
#endif
return 0;
}
